title: Thermodynamic hydration shell behavior of glycine.
abstract: Glycine aqueous solutions have been studied as a function of temperature and concentration by means of UV Brillouin and Raman spectroscopes. Brillouin spectra provided information on the average relaxation time τα related to the mechanisms of hydrogen bonds (HBs) formation and breaking. The concentration-temperature behavior of τ has been compared to the vibrational dephasing lifetime of atoms involved in HBs, as derived by a lineshape analysis of Raman spectra. We point out how it is possible to trace the thermodynamic behavior of a selected HB from Raman data. In particular, our results confirm the predominant role played in the hydration process by the water molecules surrounding the hydrophobic groups and, furthermore, evidence how at low temperature the HB strength between these molecules is greater than those found in bulk water and between glycine and water molecules.
authors.affiliation: Elettra-Sincrotrone Trieste, Area Science Park, I-34149 Trieste, Italy. francesco.damico@elettra.trieste.it
authors.forename: Francesco
authors.initials: F
authors.lastname: D'Amico
authors.forename: Filippo
authors.initials: F
authors.lastname: Bencivenga
authors.forename: Gaia
authors.initials: G
authors.lastname: Camisasca
authors.forename: Alessandro
authors.initials: A
authors.lastname: Gessini
authors.forename: Emiliano
authors.initials: E
authors.lastname: Principi
authors.forename: Riccardo
authors.initials: R
authors.lastname: Cucini
authors.forename: Claudio
authors.initials: C
authors.lastname: Masciovecchio
mesh_terms: D005998:Glycine / Q000737:chemistry*; D006860:Hydrogen Bonding; D057927:Hydrophobic and Hydrophilic Interactions; D015394:Molecular Structure; D013059:Spectrum Analysis, Raman; D013696:Temperature; D013816:Thermodynamics; D014732:Vibration; D014867:Water / Q000737:chemistry*
chemical_list: D014867:Water; D005998:Glycine